1. Field of the Invention
This invention relates to a message communication processing system and, more particularly, to a message communication processing system comprising a communication terminal for processing at least one type of media information from multimedia, and a center apparatus having a function for storing and forward exchanging messages as media information.
2. Description of the Prior Art
An electronic mail system is known in the art generally as an example of a message communication processing system of this kind and comprises a communication terminal for processing at least one type of media information from multimedia, and a center apparatus (a mail processing apparatus) having a function for storing and forward exchanging communication messages, which consist of media information. A mailbox service is available as one basic function of such an electronic mail system. When the sender of mail (hereinafter referred to simply as the "sender") transmits a message in accordance with the mailbox service, the message is registered in storing means, which is referred to as a "mailbox" for the individual (hereinafter referred to simply as the "receiver") receiving the mail, provided in the mail processing apparatus. After the message has been registered, the receiver accesses his own mailbox and extracts the message intended for him, thereby making it possible to receive the message from the sender.
Using the system described above is advantageous in that a transmission can be made without requiring that the transmitting side take into account the circumstances on the receiving side, and the receiving side is capable of receiving mail addressed to it at any time that is convenient for the receiving side.
In the mail system described above, the storage capacity of the mailboxes prepared for every receiver is limited, and therefore the maximum length of a message that is capable of being stored is stipulated in advance. In a case where the sender has transmitted a communication message in excess of the stipulated length, the mail processing apparatus suspends the processing for storing this communication message and notifies the sender of the fact that the communication message has exceeded the stipulated length.
However, in an electronic mail system which handles multimedia information, the messages are of all sorts and kinds and the amounts of information which they contain are arbitrary. For example, the amount of information in a message comprising image information generally is ten times or more that in a message comprising character information. Accordingly, in the electronic mail system described above, the following drawbacks are encountered since the maximum length of a communication message capable of being stored is fixed:
(1) If the maximum length of messages is set to be comparatively small, there will be a greater probability that messages containing a large amount of information as in the case of image information will exceed the maximum message length when mail is transmitted, and it will not be possible to register such messages in a mailbox.
(2) If the maximum length of messages is set to be comparatively large, the probability that messages having a large amount of information, as in the case of image information, will be capable of being registered in a mailbox will rise. Conversely, however, if messages having comparatively little information, as in the case of character information, are generated frequently, it will become necessary to provide the system with more memory than required, the efficiency at which memory is used will decline and, as a result, this will invite a decline in the number of messages capable of being handled by the system as a whole.
Accordingly, in a conventional electronic mail system which deals with a single medium, as in the case of a text mail system which handles character information only or a facsimile mail system which handles image information only, significant problems do not arise even if maximum message length is fixed. However, in an electronic mail system which deals with multimedia information, greater flexibility is required is terms of dealing with maximum message length.